Imides as stabilizers for polysulfone resins



Patented June 23, 1953 IMIDES AS STABILIZERS FOR POLYSULFONE RESINS JohnF. Howe and John E. Wicklatz, Bartlesville,

kla., assignors to Phillips Petroleum .Company, a corporation ofDelaware No Drawing. Application August 13, 1951, Serial No. 241,688

30 Claims. 1

This invention relates to new heteropolymeric resin compositions andtheir preparation. In one aspect this invention relates to a method forproducing thermally stable olefin-sulfur dioxide resins. In anotheraspect this invention relates to incorporating imides in anolefin-sulfur dioxide resin. In still another aspect this inventionrelates to a polysulfone resin which is resistant to thermaldecomposition.

Olefin-sulfur dioxide resins often cannot be employed satisfactorily forthe production of molded articles because of their limited thermalstability. On being exposed to elevated temperatures, the originalglass-like resin evolves sulfur dioxide, unsaturated organic compoundsand var ious volatile decomposition products of unpleasant odor,expanding into a porous, voluminous mass having a puffy structure.

Various so-called stabilizing agents have been suggested as additivesfor the olefin-sulfur dioxide resins. These additives include organicsolvent liquids and vapors, acrylic acid esters, vinyl acetate andacylating agents which supposedly act to remove occluded sulfur dioxide.When heated to the elevated temperatures necessary for injection moldingoperations, such as 300 F. or higher, these stabilizing agents becomeessentially ineffective and the resins containing them are substantiallyas unstable as in their absence.

We have discovered that olefin-sulfur dioxide resins can be renderedresistant to thermal decomposition when an imide is incorporated thereinas a stabilizing agent. When added to an olefin-sulfur dioxide resinaccording to the method of our invention imides impart excellent thermalstability to said resins.

According to this invention there is provided a process for theproduction of a thermally stable olefin-sulfur dioxide resin whichcomprises the step of adding an imide to said resin prior to the moldingstep.

Imides which can be employed in the practice of the present inventioninclude compounds of the formula wherein Z can be an aliphatic groupcontaining notmore than 18 carbon atoms or an aryl group attached inortho configuration, and R can be hydrogen or an aliphatic orsubstituted aliphatic group containing not more than carbon atoms,

or an aryl group. Typical compounds applicable to the present inventioninclude succinimide, phthalimide, N-phenylphthalimide,beta-bromoethylphthalimide and the like.

In order to effect the desired degree of stabilization from 0.2 to 10,preferably 0.5 to 5 weight per cent based on the weight of the resin ofimide is incorporated in the molding composition employed, althoughamounts outside these ranges will, to the extent added, yield theresults of the invention.

The compounds of the present invention may be incorporated inolefin-sulfur dioxide resins in a number of ways, the important factorbeing that the imide be thoroughly and intimately mixed with the resin.Thus, for example, the stabilization agent may be added to an aqueousdispersion of the resin in which the latter was prepared and both theresin and stabilizer precipitated therefrom simultaneously. An aqueousdispersion of the stabilization agent may also be added to a neutrallatex. The stabilizer may be dissolved in methanol, or other suitablesolvent and thoroughly admixed with a dry, powdered resin and thesolvent subsequently removed by evaporation or other suitable means. Thecompounds of the present invention are applicable for the stabiliaztionof olefin-sulfur dioxide resins produced by any method such aspolymerization in excess sulfur dioxide or acetone or other suitablesolvent. When operating with latices, it has usually been preferred toemploy resins produced by emulsion polymerization methods, moreparticularly resins produced by the method disclosed in copendingapplication Serial Number 8,755, filed February 16, 1948, by Willie W.Crouch and Ernest W. Cotteng- M Organic compounds which enter into thefor- PREPARATION OF l-BUTENE-SULFUR DIOXIDE RESIN An olefin-sulfurdioxide resin was prepared p-bronioallylben using the following emulsionrecipe in a stainless steel autoclave.

Parts by weight Commercial l-butene 57.7 Sulfur dioxide 88.3 Water 180Ammonium nitrate 0.5 Maprofix MM 0.6

The commercial l-butene had the following composition "Sodiumlaurylsulfate dispersing agent commercially available in the form of apaste containing about 60 per cent solids.

Mol per cent l-butene 63.2 Z-butene-cis 1.0 Z-butene-trans 12.5 n-Butane13.4 Isobutane 4.6 C3 1.0 Isobutylene 3.6 Butadiene 0.7

Example I A series of runs was made wherein solutions of imides inmethanol were added to dry butenesulfur dioxide resins obtained from alatex prepared according to the procedure described herein. Afterthoroughly commingling the resin stabilizer solution, the solvent wasremoved by evaporation. Resins so treated were tested for thermalstability in the following manner.

Two or three grams of treated resin were placed in a suitable test tubewhich was then partially immersed in a constant temperature bath held at32512" F. for varying periods. Per cent loss in weight of the resin wasdetermined at the end of said selected heating periods. The per centloss in weight provides a measure of the thermal decomposition whichtook place. Untreated controls were run simultaneously. Results of thetests were recorded in the following table:

1 Weight percent based on weight of dry resin.

Example II A run was made wherein an aqueous solution of succinimide wasadded to a sample of a coagulated, washed, and filtered resin,* that is,to a wet resin filter cake. After thoroughly comingling the resin andstabilizer solution, water was removed by evaporation. The resin soprepared was tested for thermal stability as per Example *Butene-sulfurdioxide resin as herein described.

2% succinimide 1 4 I. Results of tests are recorded in the followingtable:

Control 1 Weight percent based on weight of dry resin.

Example III A cyclohexene-sulfur dioxide resin was prepared according tothe following recipe:

Materials ggggg Cycldhexene. c 56. 8 Sulfur dioxide. 78.2 Water MaprofixMM .1"---" 1.0 Ammonium nitrate .4 0. 50

' .Pcrcent Loss in Weight at End of :r Hours Heating Temperature 325=l=2F. Time Control 3. 8 6.3 15.3 2 weight percent succinimide (based on dryresin) 3.1 5. 6 11. 6 2 weight percent N-phenylphthahmide 1 (based ondry resin) 3. 4 6. 5 14.9

1 Dissolved in water and solution added to stirred latex. Latexcoagulatcd; resin washed, and dried.

' Ground to fine powder and added to stirred latex. Latex coagulated;resin washed, and dried.

The results of tests, as indicated by the examples set out herein,demonstrate that the imides of this invention .render polysulfone resinsresistant to thermal decomposition.

Although the compounds hereinbefore mentioned are those 'preferredin thepractice of this invention other compounds which can be used include2-decy1 adipimide, Z-hexyl succinimide, and beta-bromoctyl phthalimide.

Reasonable variation and modification are possible within the scope of.the disclosure of the invention the essence of which is that theaddition of an imide to an olefin-sulfur dioxide resin results in theproduction of a thermally stable resin and that such a resin has beenproduced.

We claim:

1. In a method for the preparation of a heteropolymeric resin, formed bythe interaction of sulfur dioxide and an unsaturated organic compound,wherein the unsaturation is a double bond between adjacent carbon atomsand which will polymerize with sulfur dioxide to form a .resin theimprovement which comprises incorporating an imide into saidheteropolymeric resin.

2. In a method for the preparation of a heteropolymeric resin, formed bythe interaction of an unsaturated organic material, wherein theunsaturation is a double bond between adjacent carbon atoms and whichwill polymerize with sulfur dioxide to form said resin, and sulfurdioxide, the improvement which comprises incorporating into saidheteropolymeric resin an imide characterized by the formula wherein Z isa radical selected from the group consisting of an aliphatic groupcontaining not more than 18 carbon atoms, and an aryl group attached inortho configuration; and R is a radical selected from the groupconsisting of hydrogen, an aliphatic group containing not more thancarbon atoms, a substituted aliphatic group containing not more than 10carbon atoms and an aryl group.

3. A method for the preparation of a heteropolymeric resin whichcomprises preparing an aqueous emulsion of an unsaturated organiccompound, wherein the unsaturation is a double bond between adjacentcarbon atoms and which will polymerize with sulfur dioxide to form saidresin and sulfur dioxide in a molecular excess over said unsaturatedorganic compound, effecting interaction of said unsaturated organiccompound with said sulfur dioxide to form a latex, intimately admixingwith said latex an imide characterized by the formula wherein Z is aradical selected from the group consisting of an aliphatic groupcontaining not more than 18 carbon atoms, and an aryl group attached inortho configuration; and R is a radical selected from the groupconsisting of hydrogen, an aliphatic group containing not more than 10carbon atoms, a substituted aliphatic group containing not more than 10carbon atoms and an aryl group, and recovering from the resulting latexadmixture a resin having improved resistance to thermal decomposition asa product of the process.

4. The method of claim 2 wherein said unsaturated organic material isselected from the group consistin of an open chain mono-olefin and amono-cyclic mono-olefin.

5. The method of claim 3 wherein said unsaturated organic compound isselected from the group consisting of an open chain mono-olefin and amono-cyclic mono-olefin.

6. A method for the preparation of an olefinsulfur dioxide resin,comprising emulsifying a liquid olefinic organic material in aqueousemulsion and in the presence of sulfur dioxide in a molecular excess ofsaid olefinic organic compound, effecting interaction of said olefinicorganic compound with sulfur dioxide to form a latex, introducing intointimate admixture with said latex an imide characterized by the formulawherein Z is a radical selected from the group consisting of analiphatic group containing not more than 18 carbon atoms, and an arylgroup attached in ortho configuration; and R is a radi cal selected fromthe group consisting of hydrogen, an aliphatic group containing not morethan 10 carbon atoms, a substituted aliphatic group containing not morethan 10 carbon atoms and an aryl group and recovering from the resultinglatex admixture a resin having improved resistance to thermaldecomposition as a product of the process.

'7. A composition of matter comprising a heteropolymer of an unsaturatedorganic material, wherein the unsaturation is a double bond betweenadjacent carbon atoms and which will polymerize with sulfur dioxide toform said heteropolymer and sulfur dioxide, and an imide.

8. The method of claim 6 wherein said olefinic organic material isselected from the group consisting of an open chain mono-olefin and amonocyclic mono-olefin.

9. In a method for the preparation of an olefinsulfur dioxide resin, theimprovement which comprises incorporating into said olefin-sulfurdioxide resin an imide characterized by the formula wherein Z is aradical selected from the group consisting of an aliphatic groupcontaining not more than 18 carbon atoms, and an aryl group attached inortho configuration; and R is a radical selected from the groupconsisting of hydrogen, an aliphatic group containing not more than 10carbon atoms, a substituted aliphatic group containing not more than 10carbon atoms and an aryl group.

10. A composition of matter comprising a heteropolymer of an unsaturatedorganic material, wherein the unsaturation is a double bond betweenadjacent carbon atoms and which will polymerize to form saidheteropolymer and sulfur dioxide, and an imide characterized by theformula wherein Z is a radical selected from the group consisting of analiphatic group containing not more than 18 carbon atoms, and an arylgroup attached in ortho configuration; and R is a radical selected fromthe group consisting of hydrogen, an aliphatic group containing not morethan 10 carbon atoms, a substituted aliphatic group containing not morethan 10 carbon atoms and an aryl group.

11. The composition of claim 10 wherein the unsaturated organic materialis selected from the group consisting of an open chain mono-olefin and amono-cyclic mono-olefin.

12. A latex comprising an aqueous emulsion of a resin formed from sulfurdioxide and an unsaturated organic compound wherein the unsaturation isa double bond between adjacent carbon atoms and which will polymerizewith sulfur dioxide to form said resin, and an imide.

13. A latex comprising an aqueous emulsion-f a resin formed from sulfurdioxide and an unsaturated organic compound wherein the unsaturation isa double bond between adjacent carbon atoms and which will polymerizewith sulfur dioxide to form said resin, and an imide characterizedbythe-formula o H ,o :z

wherein Z is a radical selected from the group consisting of analiphatic group containing not more than 18 carbon atoms, and an arylgroup attached in ortho configuration; and R is a radical selected fromthe group consisting of hydrogen, an aliphatic group containing not morethan 10 carbon atoms, a substituted aliphatic group containing not morethan 10 carbon atoms and an aryl group.

14. The method of claim 1 wherein the imide is succimmide.

15. The method of claim 1 wherein the imide is phthalimide.

.16. The method of claim 1 wherein the imide is N-phenylphthalimide.

17. The method of claim 1 wherein the imide is fl-bromoethylphthalimide.

18. The composition of claim 7 wherein the lmideis succinimide.

19. The composition of claim '7 wherein the imide isN-phenylphthalimide.

20. The composition of claim 7 wherein the imide isB-bromoethylphthalimide.

21. The composition of claim 12 wherein the imide is succinimide.

22. The composition of claim 12 wherein the imide is phthalimide.

23. The composition of claim 12 wherein the imide isN-phenylphthalimide.

24. The composition of claim 12 wherein the imideisfl-bromoethylphthalimide.

"25. The method of claim 2 wherein the unsaturated organic material is1-butene.

'26. The method of claim 2 wherein the unsaturated organic material iscyclohexene.

27. The composition of claim '7 wherein the unsaturated organic materialis l-butene.

28. The composition of claim 7 wherein the unsaturated organic materialis cyclohexene.

29. The composition of claim 12 wherein the unsaturated compound isl-butene.

'30. The composition of claim 12 wherein the unsaturated compound iscyclohexene.

JOHN F. HOWE. JOHN E. WICKLATZ.

No references cited.

1. IN A METHOD FOR THE PREPARATION OF A HETEROPOLYMERIC RESIN, FORMED BYTHE INTERACTION OF SULFUR DIOXIDE AND AN UNSATURATED ORGANIC COMPOUND,WHEREIN THE UNSATURATION IS A DOUBLE BOND BETWEEN ADJACENT CARBON ATOMSAND WHICH WILL POLYMERIZE WITH SULFUR DIOXIDE TO FORM A RESIN THEIMPROVEMENT WHICH COMPRISES INCORPORATING AN IMIDE INTO SAIDHETEROPOLYMERIC RESIN.